Machine for cutting sheet material



April 14, 1931. c. B. MAXSON CHINE FOR CUTTING SHEET IATERIAL Filed Aug. 28, 1928 mwen zor Patented Apr. 14, 1931 UNITED TATES PATENT f OFFICE CHARLES BENJAIHT mson', WESTEBLY, RHODE ISLAND, ASSIGNOR 0F ONE-HALF '10 JULIAN W. MAISON, OF WESTERLY, RHODE ISLAND CHINE I08 CUTTING SHEET MATERIAL Application fled August 28, 1828. Serial No. 302,585.

The present invention relates to machines for cutting sheet material.

A machine of a type in common use today for cutting web material, like aper, into sheets, comprises a stationary lfe with which cooperates a movable knife mounted u on a rotary drum. The web is fed from a ve, at a downward incline, into the space between the stationary knife and the drum 1 and toward the under side of the drum, and

is out once corresponding to every revolution of the drum. In order to produce long sheets, it is necessary to feed the web at hi h speed. It is obvious, however, that t e speed of the web must not be materially greater than the peripheral s eed of the rotating knife. As a matter 0 fact, in actual practice, it has never heretofore been possible, so far as known, particularly at high speeds, to have the web even approach this speed of operation of the knife. The knife, after it has cut the web, has a tendency to buckle the cut end of the web, with the result that the successively-cut sheets can not be delivered in smooth, flat condition, but become jumbled up into a hopeless mass. This tendency exists because the rotary knife and the web approach each other toward the stationary knife from opposite directions.

It is, accordingly, an object of the present invention to improve upon present-day methods of and machines for cutting webs. To this end, the invention resides in the improved machine a preferred embodiment of which is hereinafter described, illustrated in the accompanying drawings, and defined in the appended claims.

In the accompanying drawings, Fig. 1 is a diagrammatic elevation of a paper-cutting machme embodying a preferred embodiment of the present invention; Figs. 2, 3 and 4 are diagrams illustrative of the prior art; and Figs. 5, 6 and 7 are corresponding diagrams illustrating the present invention.

A web of paper 2 is adapted to be fed by any suitable feed mechanism, such as the feed rolls 4 and 6, to a stationary knife 8 with which cooperates a movable knife 10 mounted upon a drum 12 that is disposed to one side .of the stationary knife 8 and rotates about an axis 14. The rotary knife 10 thus moves toward the stationar knife in a forward direction. Correspon ing to each revolution of the drum 12, a sheet of paper, that is fed between the knives from a point to the other side of the stationary knife 8 in a direction toward the underside of the drum 12, will be cut by the knives. If the cutter 10 is operated at very high speed, and if the web is fed at a comparably high speed, there is a tendency for the cut end 18 of the web to lag behind the knife 10, as shown in Fig. 3, and thus become deflected upward. This is because the speed of the end 18 of the sheet in the direction of travel of the sheet is greater than the right-line component of the speed of the knife 10 in the same direction, even though their absolute speeds be the same. The result is that the knife 10, blocking the travel of the end 18 of the sheet, causes the said end 18 to catch on the knife 10, and accumulate in 100 form in back of the knife 10. Though t e operation has thus been described in connection with high speeds, the principle applies also to low speeds.

As the knife 10 rotates further to the position shown, for example, in Fig. 4, the deflection 20 in the cut end 18 of the web becomes more pronounced, with the result that ultimately, after another sheet has been cut, its front end 18 becomes so buckled up as to prevent proper delivery of the sheet.

According to the preferred embodiment of the invention that is herein illustrated and described, however, a projection 22 is mounted in spaced relation and in close proximity to the knife 10 at a point directly rearward of the knife 10 in the direction of rotation of the knife. At certain speeds and under certain conditions, as before stated, the end 18 of the advancing web has a tendency to engage the knife 12 and curl or bulge up on top of it, as illustrated in Fig. The projection 22, however, brushes or directs or deflects the advancing end 18 of the web downward, past the stationary knife 8, thus preventin the end 18 of the web from buckling up. T e projection 22, in the form illustrated, consists of a long bar, pplroximately of the'web downwardly past the stationary equal in length to the length 0 e knife 10, and screwed in place by a plu'ralit of screws 24 that extend at intervals along t e knife 10.

The 0 ration is at first somewhat as illustrate in Fig. 6. As the-cutter 10 rotates further, to the tion of Fig. 7, corresponding to the position of Fig. the end 18 of the .web assumes a sition somewhat as shown in the said i 7, permitting the pro r delivery of the s eet.

odifications will readily suggest themselves to persons skilled in the art, and all such are considered to fall within the present invention, as defined in the appended claims.

What is claimed is:

1. A machine for feeding and cutting a web having, in combination, a stationary knife, a rotary drum having a cooperating knife projecting therefrom, means for rotating the drum, means for advancing the web between the knives in a direction toward the underside of the drum to cause the web'to become out by the knives, the speed of advance of the web being such relatively to the speed of rotation of the rotary knife that, after the knives have cut the web, the advancing, cut end of the web has a tendency to engage the rotary knife and curl or bulge on' top of it, and a member projecting from the drum in spaced relation and in close proximity to the rotary knife at a point directly rearward of the rotary knife in the direction of rotation of the rotary knife for directin the advancing, cut end of the web downwar ly past the stationary knife toward the underside of the drum.

2. In a machine for feeding and cutting webs, a stationary knife, a movable knife, means for feeding a web in a diagonal direction between the knives at a speed, relatively to the movable knife, such that, after the knives have cut the web, the advancing cut end of the web has a tendency to engage the movable knife and curl or bul u on top of it, and means for directin ti advancing cut end of the web downwar y past the stationary knife, I

3. In a machine for feeding and cutting webs, wherein the web is advanced from a point to one side of a stationa knife into the path of travel of a cooperatmg movable knife that is moved toward the stationary knife in a forward direction from a point to the other side of the stationary knife, the speed of advance being such, relatively to the speed of themovable knife that, after the knives have cut the web, the advancing cut end of the web has a tendency to engage the movable knife and curl or bulge up on top of it, means disposed in spaced relation and in close proximity to the movable knife at a point directly rearward of the movable knife in the direction of movement of the knife for directing the advancing cut edge knife.

In testimony whereof, I havehereunto subscribed m QHA name. LES BENJAMIN MAXSON. 

